Antibiotic susceptibility of bacterial strains isolated from urinary tract infections in Poland.

Worldwide data show that there is increasing resistance among urinary tract pathogens to conventional drugs. The aim of this study was to obtain data on susceptibility patterns of pathogens responsible for urinary tract infections (UTIs) in Poland to currently used antimicrobial agents. A multicentre study of 141 pathogens from hospital-acquired infections and 460 pathogens from community-acquired infections was carried out between July 1998 and May 1999. The most prevalent aetiological agent was Escherichia coli (73.0%), followed by Proteus spp. (8.9%) and other species of Enterobacteriaceae (9.6%). Few community infections were caused by Gram-positive bacteria (2.2%). Gram-positive cocci were isolated more frequently from a hospital setting (14.1%) and the most common were Enterococcus spp. (8.5%). Pseudomonas aeruginosa was found only among hospital isolates and was responsible for 10.7% of infections. E. coli isolates from both community and hospital infections were highly susceptible to many antimicrobial agents with the exception of those isolates producing extended-spectrum beta-lactamases (ESBLs). Of all Enterobacteriaceae tested, 38 strains (6.9%) were capable of producing ESBLs.

Studies on the regeneration of rat intestinal epithelium after exposure to cyclophosphamide.

Cyclophosphamide caused changes in Paneth cells. The relationship of these changes to the proliferative reaction of the intestinal epithelium requires a more complete knowledge of various physiological functions of Paneth cells.

Intestinal epithelium regeneration in rats receiving methotrexate and a trial of regulating this regeneration with pentagastrin and glucagon.

The study was carried out in three groups of rats: group I of 36 rats received methotrexate, group II of 36 rats were given methotrexate, pentagastrin and glucagon, group III of 12 rats served as control. For histological examination the ileum was taken from the animals killed on days 1, 2, 3, 4, 7 and 9 after the last injection of methotrexate. Besides histological examinations the mitotic index and the number of cells in crypt longitudinal-section were determined. Relatively low doses of methotrexate caused characteristic changes in the intestinal mucosa: disappearance of mitotic figures, shortening of crypts particularly on the first day after the last dose of methotrexate. On the following days regeneration processes were noted causing an excessive epithelial proliferation observed up to the 9th day after the last dose of methotrexate. This indicates that the mobilized mechanisms of epithelial proliferation stimulation exert their effect fairly long. In the group receiving methotrexate administration of pentagastrin and glucagon contributed to the increased number of mitoses in crypt epithelium and the number of cells on crypt longitudinal-section. These observations are an evidence of a beneficial effect of the hormones administered to the rats in the regeneration of the ileal epithelium damaged by the cytostatic agent.

Histological studies on the regeneration of small-intestine epithelium of rats irradiated with sublethal doses of X rays.

The dynamics of regeneration of small-intestine epithelium was studied in rats irradiated with X-rays in sublethal doses of 550, 600 or 750 R. Sixty-two irradiated and 22 control animals were used in the experiment. They were killed 1,2,4,6,8,14 and 25 days after the irradiation. Specimens of duodenum and jejunum were examined histologically, the sections being stained with H.E. and p.a.S. Already 1 and 2 days after irradiation the intestinal villi became shorter and deformed. The blood vessels were damaged, the enterocytes showed features of degeneration and vocuolization, the epithelium was detached by the exudate which accumulated in the stroma. Irradiation markedly disturbed the regeneration of intestinal epithelium in the period from the 1st to the 6th day. Cytological calculations indicate that on the 1st and 2nd days after irradiation the number of epithelial cells of the villi, and particularly of young cryptal ones, markedly dropped. On the 4th and 6th days increased proliferation of young cryptal cells considerably surpassed the physiological rate. The accompanying disturbances in differentiation consisted in a decreased acidophilic to basophilic cells ratio and in retardation of maturation of goblet cells. The absolute number of goblet cells was increased, as well as their proportion to the number of enterocytes.